UV ABSORPTION-SPECTRA, KINETICS AND MECHANISM FOR ALKYL AND ALKYL PEROXY-RADICALS ORIGINATING FROM T-BUTYL ALCOHOL

Alkyl and alkyl peroxy radicals from 1-butyl alcohol (TBA), HOC (CH3)2CH2. and HOC(CH3)2CH2O2. have been studied in the ps phase at 298 K. Two techniques were used: pulse radiolysis UV absorption to measure the spectra and kinetics, and long path-length Fourier transform infrared spectroscopy (FTIR) to identify and quantify the reaction products. Absorption cross sections were quantified over the wavelength range 220-320 nm. At 240 nm, sigma(HOC(CH3)2CH2) = (2.4 +/- 0.3) x 10(-18) and sigma(HOC(CH3)2CH2O2) = (3.4 +/- 0.5) X 10(-18) cm2 molecule-1 have been obtained. Observed rate constants for the self-reaction of HOC(CH3)2CH2. and HOC(CH3)2CH2O2. radicals were found to be (3.0 +/ -0.5) x 10(-11) and (7.8 +/- 1.5) X 10(-12) cm3 molecule-1 s-1, respectively. For the reaction of the alkyl radical with O2 in 1 atm SF6 a rate constant of (1.8 +/- 0.2) x 10(-12) cm3 molecule-1 s-1 was found. k(HOC(CH3)2CH2O2. + NO) and k(HOC(CH3)2CH2O2. + NO2) were determined to be (4.9 +/- 0.9) X 10(-12) and (6.7 +/- 0.9) x 10(-12) cm3 molecule-1 s-1, respectively. In the FTIR experiments products were studied using chlorine-initiated oxidation in TBA/N2/Cl2 and TBA/N2/O2/Cl2 mixtures.